Sheet annealing furnace



July 5,1932

P. A. MEEHAN SHEET ANNEALING FURNACE Filed April 6, 1928 3 Sheets-Shegt 1 INVENTOR B L 4. MEL /mw ATTORNEY July 5, 1932.

P. A. MEEHAN' SHEET ANNE'ALING FURNACE 3 Sheets-Sheet 2 INVENTOR PHI/Z A? Mff/IH ATTORNEY Filed April 6, 1928 Patented July 5, 1932 umren PAUSE A; Mnmmm-or; CISEVELAND, onto, AssrGnon, [BY ,miisnnhssroivmnnrs; "r:

swmnnrnnnnssnnn comaonnrron; or PITTSBURGH, rENNsYLvA-mmn oonromrron or PENNSYLYANIA'.

1 a lication. filed'i April 6,

. 'Ehapresent invention relates to. annealing furnaces wherein sheetlmaterial, is continu: comely-passed through aidesired heat'treating process. The; object of; my invention isto provide; an; improved, construction and; ar-

rangement of an; annealing furnace of. this a-better understandingottheinvention', however,-.-and' the advantages posse'ssedby it reference; shouldbe had tothe; accompanying dnaw-ings andldescriptive matter in Which-,1 have illustrated and-described preferred enibodiments of the invention. i

Of the drawings; j l Fig. l is a-diagrammaticplanaviexvvofone embodimentotamyrinvention;;. g V

Fig. 21s.- a diagrammatic elevation L of the apparatus-ot-Fig. 1;

Fig, 3 lSyEItSQClSlQIliOHrlrhGf-llllfi 3 3 otllig .12; Fig; isa section on'theline Fig, 11; Fig 5 is a-section on -theline-5j- 5t-ofl*ig. 1;; Fig. (Sisasection on theline-B-efiotFig, 11; Fig. '7 is aisectioneonthe line 'Y-TotFig 1; Fig. 8 is a section-on theline8. 8-oi; Fig 1; 2 Fige.9=is1an=enlargedyelevationof the carriersofmyinvention;v V V j Fig. 10' is anienda view oi the apparatus shown-inFig Q; j c, Fig. 11 is a section'on the; line;1l -l l of Fig.9; Fig; 112. is a verticalisection through-the burner. section ot azfnrnacehaving almodified tormzot'carriergz Fig. .13;isza similar. se. tion showinga D'I'Odii fied arrangement m r. 141a views similan toHEig; 1'31. of? a fourth arrangement 15;is;a diagrannnatic plan'- view of the "arrangement shown: in Fig. 1-4;

V Fig: 16 is an enlargedfvieW-ot .thesheet terial'holding: means of Fig; 12;]and1 ig; 17 'isazvievv showing asmodified-form of; sheet material holding'means.

InFigS 1 and 2a zfthe drawings I have diagrammatically illustrated SHEET A-NnEnLmG FURNACE 1928: Serial nc; 267,527}:

bodiment ofmy invention in whicha'hori5 zontal annealing furnaceA comprisesacom bmed. preheating and heating zone a and a cooling zone I) longitu'dlnall'y arrangedgalon the furnace. Sheets ot metallic materia suitably supportedon an endless. carrier B. I

are passed into the entrance end A, of the furnace,rthrough the preheating andheatin I sectionswherein theyare heatedi'to a desire temperature and attercbeing cooled in the cooling section b are passed outthrough, the exit, end At: 7 Sprocketiwheels (land. C are positioned at} points longitudinally spaced from the opposite" ends of the furnace for regulating the movement of the: endless eon:

veyor B. 1 As illustrated in :Fig. 1 onelrun of the conveyor passes through the furnace, A while the' return run passcsexternally of the furnace. A loading platformDispositioned between the, 'spro,cket wheel; C and th'e -entrance. end As; At theopposite, end ofthe furnace and positionedbetween that end and thesprooketC' is anxunloading platformlE where thesheet material'is remove difromtjh'e yo f H 1 The annealing furnac eis substantially reotangular in cross-section with a vertical; turnace, chamber A e'Xtending'v-theen'itire length of the furnace. The heating andcoolingsecftions ofthe furnace chamber have a Width approximately half of the. height and are .-enclosed by vertical refractorywalls A reins forced at their outer sides bya structural steel frame R; The upper end ot'thefilrnac'e jchamberj is tapered and connected to, the at' mosphere a narrow slot A? extendin'g't'lie lengthoffthefurnace. longitudinal metal} lic trough ismounted, on the 7 top of the furnace at eaQh side of the slot A The frame F comprises verticalt beams FQF.

and F connected byhorizontal-v cross. beams F iAllongitudinal steel framework F is arranged on theto'p of the furnace and'lsuit- .ablyi brac ed', from the "vertical, beams F v In the combined preheating and heating section a arearranged upper and, lower sei ries 5 of longitudinally spaced burner metes G eachof which ispositioned i'rin horizontal V furnace.

at its outer end. The inner end G of each nozzle is tapered and turned downwardly to discharge a combustible mixture of gas and air into the furnace chamber. The portion of the sidewall of the chamber adjacent the discharge end of the upper nozzles projects inwardly and upwardly to'form a small vertical battle H for deflecting the combustiblegases into the upperhalf of the furnace chamber. The lower series of nozzles discharge against an adjacent recessed block H in the floor of the combustion chamber which deflects the burning mixture upwardly.- The nozzles are preferably arranged on both sides of the furnace chamber and provide a uniform heating efl'ect throughout the height of the chamber. A control valve G is rovided for each burner nozzle for regulating the heating effect thereof. p

As shown in Fig. 3 the portion of the preheating zone adjacent the entrance end of the furnace is enlarged and formed with a pair of lateral conduit passages J,, to the bottoms of which are connected verticalpassages J. -The passages'J discharge into a horizontal off-take flue J at the outer end of which is located an exhaust, fan (not shown). The upper. end of each vertical ipassageJ is provided with a damper plate 3 for controlling the flow of gases. This arrangementprovides a longitudinal circulation of heatinggases from the burner section through the "preheating zone and exhaustion of the gases to a suitable heat recovery device. I

The cooling section b, as shown in Figs. 2 and 6, is'provided with a series of vertically looped pipes K supported on each side wall ofthe furnace chamber. 'Each pipe has a cooling water inlet K and an .outlet K The portion of the furnace chamber between the end of the burner section and the cooling section isdecreased in width to minimize any" flow of gases between the two sections of the furnace as shown in Figs. 1 and5. I 'The endless carrier of my invention comprises longitudinal sprocket wheels C and C located atopposite ends of the furnace. The sprocket wheel C is driven through a pair of gears G in any suitable manner to move the carrier chain. At'longitudinally spaced points along the chain cruciform j shaped hangers B are suspended,and each of which the frame F. Depending from the lower end form the bearing for a pair of wheels B" adapted to roll' on'tracksF supported by of each hanger is a hook B for supportinga metallic carrier cage M within which the sheets of material are carried through the Each cage M comprises a rectangular frame having upper and lower; cross bars M andM respectively, connected by a pair of verti'cal rods' M The" frame is detachably connected to a pair of hooks B by apair of rods M having a closed loop at their upper ends. A short U-shaped plate A is supported on each rod Mand dips into a sand seal in the troughs A to seal the top of the furnace chamber as shown in Fig. 4, The bar M is provided at each end with a fixed projecting member M having a recess M therein. A U-shaped holding frame N. of slightly greater width than the'frame M has the low er ends of its legportions pivotally mounted in forks formed in the outer ends of each bar M as shown at- N. When the frame N is in its normal vertical position, the horizontal frame bar N fits into the recessed portion M of the projection M The frame N is locked in this position by a pair of latch members 0 pivotally mounted atopposite ends of the bar M adjacent the members M Each latch member O is formed with a downwardly projecting portion 0 adapted to fitover the horizontal bar N 2 and hold the frame N in the vertical position. Each locking member is also pro vided with a beveled surface 0 at the underside of it-s' outerlend. Each cage Mis pivotally connected to the adjacent cages bya tongue member M projecting from one end of the bar M and fitting between a pair M passing through aligned openings in the tongue members.

As shown in Figs. 1 and 10 a tripping bar P- ismounted adjacentthe driving sprocket C and provided with'a'beveled edge portion P adapted-to'contact with the beveled surface O? of each pivoted locking memberO. The inclination of the bar portion P increases along'its'lengthinlthe direction of travel of the carrier whereby the latch member israised to the position shown in dotted lines in Fig. 10 torelease the frame N from the vertical position. 7

A guide plate Qlis mounted on the loading-platform D and provided-with angular sections Q and Q extending towards the endless carrier. The section Q, is connected to one end of the bar P-and is arranged to guide the frame Non its release from the locking position. The relative arrangement of the "parts when the unlocked frame N is moving along the loading platform is shown in Fig. '7. The guide section Q raises the a frame N until the frame Jcam's thelatch O upwardly and theparts are again lockedin position. i 4

' Substantially the same arrangement of the tripping barand guide plates is provided at and guide the frame N into the position shown in'Fig. 8. The section Q againre- Stores the frame N to its locking position and paratus described, the sheetsof material tobe' heat treatedare placed onthe loading platfarm-D and-as the cages-come into th position shown'in Fig'. 7 the sheets of material are placed in the cages Withtheir side edge portion contacting Withfthe bar M of the cage. separately or in packs of two or more and simultaneously heat treatedi Thesheets are carried throughthe furnace in" the vertical position at the desired rate for proper treat:- ment and on emerging; from V the furnace are automatically dischargechonto the unloading platform by the action of thetrippingbar at that point; The c'agesare locked after being unloaded-and returned to the entrance endof'the furnace. Where it is desired to heat treat continuous strips of material, the

material may be passedfrom areel into the cages When in their loading position and taken ofi onto a second reel at the exit end of the furnace after the cages are unlocked j My invention is not-restricted tothelongitudinal form of furnace and it can be built" in circularform with the furnace occupying three-fourths ofthe circumference and the material handling and carrier driving means the remaining portion of'the-circle; V,

, The invention disclosed is characterized by the simple and effective provisions for passing the sheet material through the furnace. The main advantages of supporting the sheets on'theirsi'd-e edges are to prevent the surfaces of the sheets from-being marred by contact'with supporting- 'rollsas usually occurs when sheets are passed through in the horizontal position and to'prov-ide a uniform heat treatment of all portions of the material in a furnace' constructed as described. The 'portionsof' the conveyor and the cage exposed tothe furnacetemperature's are preferably made" of light heat resistant metal or alloy rather than heavy sections of cast iron or steel. The loading an'd u'nloading provisions are especially simple" in-con stuction and eifective in operation.

- My invention is notre'strict'e'd' to the use 'of fuel burner nozzles in the sidewalls of the furnace chamber as the heating meansthe'refor, and I contemplate using electrical heating means in the form of metallic, carbon or silicon carbide resistance elements-mounted" on "the side walls of the furnacechamber inlieu of the "burner nozzles; Such elements may be mounted onthe flooro'f thechambe'r alone or in conjuncjti'on with other-elements mounted 'on theside Walls. a a V In Figsv12; 13, l l and-lh, Ih'ave illustrated a modified formof sheet material holding means which is of'co'ns'iderably less size and eight than the carrier-cagesdescribed thus reducing the accessory Weight to be; heated The sheet" can beplaced in the cages andcooledduring eachpassage through the furnace; In A this construction a each of the hooks B hsupportsa verticalirod R having a transverse member R's at its lower endfrom which dependvertical" rods R?-and Re; 1 Each of the latter has a metallic jaw blockR and R respectively, secured to its lower end. The block 'Rt" is formed with a ball R? arrangedtof fit in a grooveltlin the blockRi At the entranceend of the furnace a sheet a is placed between the 1 blocks R and R and theblocks'passedbetweena pair of spring pressed rollers S and S or anysuitable mechanical means for causing the-blocks to securely grip the sheet therebetw'een. As,

R 'ii's automatically released and the sheet 1 p 7 material removed. The slight: deformation of'the upperredge of the sheet is removed during the cold rolling operation on the annealedsheet, Y a Y In Fig. 17 another type of holding means is shown for holding a metallic sheet atits upper edge. In this construction each pair of: blocksRt and R is secured together by a threaded bolt R Theblock R is provided Witha recess Tin whicha pin T 'is sli'd'ably V mounted The pin T'- is-arranged to pass through an. opening T in'the block R and into a' passa'ge T 'in the blockRfl A sheet of material is inserted 'between the adjacent f'aces 'ofthe blocks and the pin T driven through the upper edge portion of thetmae teri'a]; The sheet is thus positivelyheld during its' -passage through the furnace; -The resulting horizontal series of small holes: in each? sheet is not' disadvantageous for, some uses of the material, V

. Whilethe annealing furnace shown is described as'havinga single line of carriers transporting the. goods in one direction through the furnace and having the return run o'fth ecarrier externally of the furnace,

my invention :isnot necessarily limitedto that construction and the furnace may beconstructed with twin carriers moving in the same direction through parallel heating chambersor" single line o'f carriers in a continuous loop moving-in oppositev direc- I tions through the furnacecham er;

- In-FigJIB isshowna single, conveyor V supporting twin carrier's V" and. VWhich move through parallel-heating: chambers V and V, "respectively, separated by a vertical Wall"V Thisarrangement' can be modified for movement 'of'the. carriers in opposite directions throughthe furnace.

In: Figs. 14: and15, a'single line of-carrriers l -V is shown in. a. continuous loop with both nuns: W and W of the 'conveyorxwithirr' the ,furna c'erstructure; I rr-tlris arrangemeiitzthfe sheets are carried-during only one runof the conveyor or if desirableunloading and loading stations are arranged at each loop portion W and the'material moved throughothe .fur-

- nace chamber inopposite directions While in accordance with the provisions of the statutes, Ihaveillustrated and described the best forms of embodiment of my invention now known tome, it will be apparent to those skilled in the art that changes may be made intheformof the apparatus,

disclosed without"departingfrom the spirit I of my invention as set forth in the appended 'jacent one end of the furnace for automatically opening said cages to receive the sheet material. 7 c

2. In a horizontal furnacehaving arfurnace chamber therein, means for passing sheet material through said furnace chamber in a vertical plane comprising an endless conveyor and a plurality of material carrying cages supported from said conveyor, meansfor automatically opemng sa d cages; to recelve the sheet material, and means for locklng said cages after the material is placed-therein.

3. In a horizontal furnace having a furnace chamber therein, means forv passing sheet material through said furnace chamber in a vertical plane comprising an endless conveyor, a

plurality of material carrying cages supported by said conveyor, each of said cages comprising a fixed and a pivoted frame member, and-meansfor locking said pivoted frame memberto said fixed frame member.

4. In a horizontal furnace having a furnace chamber therein, means for passing sheet material through said-furnace chamber in a vertical plane comprising an endless conveyor, a plurality of material carrying cages supported by said conveyor, each of said cages comprising a fixed-and a pivoted framemember, means for. locking said pivoted frame member in'a vertical position, and automatic means forunlatching said locking means to release said pivoted frame member.

5; In a horizontal furnace having a furnace chamber therein, means for passing sheet material throughsaid furnace chamber in a vertical plane comprising anzendles's conveyor,

a plurality of material'carrying cages supported by said conveyor, eachof said cages comprising a-fixed and a pivoted frame member, means for locking said pivoted frame member to said fixed frame member, means for releasing said locking means, and guide terial through said furnace chamber in a. ver-- tical plane comprising an endless conveyor, material carrying cages supported by said endless conveyor and each comprisinga fixed frame, a second frame pivoted on said rigid frame and locking means for holding said pivoted frame in a vertical-position, and a trippingbar arranged; to contact with said locking-means for rasing said locking means to release said pivoted framefrom its vertical position.

7. In a horizontal furnace having a furnace chamber therein, means for passing sheet material through said furnace chamber comprising an endless, sprocket chain having one run extending above said furnace chamber, hangers secured to spaced points on said chain, a track mounted above said furnace chamber, track engaging wheels supported by said hangers, and sheet material carrying means deta'chably supported by said hangers. V

. 8. In a horizontal furnace having a furnace chamber of relatively narrow. Width therein, means for passin'gsheet material through said furnace chamber comprising an endless chain having one run above said furnace chamber, a track positioned above said furnace chamber, track engaging wheels suspended from said chain, a plurality ofsheet material carrying frames supported by said chain, and each of said frames beingpivotally connected to the frames adjacent thereto, whereby adjacent frames are held in longitudinal alignment. 9. The combination witha horizontal annealing furnace comprising a longitudinally extending furnace chamber of relatively small width having heating and cooling sections arranged along the length of said chamber, of means for passing sheet material through the heating and cooling sections of said furnace chamber, in a vertical plane extending longitudinally of said furnace chamber, said meanscomprising an endless conveyor 7 arranged above and externally of said furnace chamber, means for driving said conveyor, means connected to said conveyor for supporting said sheet material during its passagejithrough thesections of said chamber, and means postioned adjacent the ends of said furnace for-automatically actuating said material supporting means to arrange the latter in positions to receive and discharge said material;

7 10. The combinationwith a horizontal furnacehaving a horizontally elongated furnace chamber .of relatively narrow Width therein, of means for passing sheet material through saidfurnace chamber comprising an endless chain, and rectangular'cagesin which said material is arranged in an upright pOSl-l tion secured at spaced points on said chain,

and means connecting and holding adjacent v cages in longitudinal alignment. v 11. The combination with a horizontal furnace having an elongated furnace chamber therein, of means for transporting sheet material in an upright position through Said furnacechamber, said means comprising an endless conveyor mounted externally of said chamber and lockable means supported from said conveyor for engaging said sheet material, and stationary means adjacent the path of movement of said lockable means for automatically locking and unlocking the latter.

12. The combination with a horizontal fur: nace having an elongated furnace chamber therein, of means for passing sheet material to be heat treated through said chamber with its main surfaces exposed to the sides of said chamber, said means comprising an external 1 support moving longitudinally above said chamber, a two section carrier secured to said support, and locking means holding said carrier sections togethenand means adjacent each end of said chamber for automatically actuating said locking means to open and close said carrier. c r i 13. The combination with a horizontal furnace having a horizontally elongated furnace chamber of relatively narrow width therein, of means for passing sheet material through sald furnace chamber in an upright position, and means for uniformly heatj c ing said material during its passage comprising an upper and lower row offluid fuel burners in said furnace chamber at each side of said material, a refractory baflie adjacent the discharge end of the fuel burners in said upper row and a recessed block'adjacent the discharge end of the fuel burners in said lower row, whereby the combustible mixture discharged from said fuel burners is deflected V upwardly in said furnace chamber. 7

Signed at Cleveland, in the county of Guyahoga and State of Ohio, this third day of April, A. D. 1928. 7

PAUL A; MEEHAN. 

